In certain electric motor constructions, the motor end shields are mounted directly on the stator, which is formed from a stack of laminations. The end shields are usually secured with a threaded screw or a through-bolt. Depending upon the types of materials used, however, the end shield may move relative to the stack. Because the rotor is mounted in the end shields, movement of the end shields results in movement of the rotor, which can affect the operation of the motor. This can particularly be a problem with steel end shields, because of their smooth hard surfaces.